In general, fluorine-containing elastomers are superior in heat resistance and oil resistance and are used in various industrial fields such as general machine industry, industry relating to antipollution technique, automobile industry, shipping industry, aircraft industry and hydraulic machine industry. Especially, since the fluorine-containing elastomers which are subjected to vulcanization with peroxides are markedly excellent in chemical resistance, they are used in the field of sealing lubricating oils containing a large amount of additives and further used where they directly contact with acids or bases.
However, when the fluorine-containing elastomers which are subjected to vulcanization with peroxides are compared with polyol-vulcanizable fluorine-containing elastomers which are subjected to vulcanization with aromatic polyol compounds which are mainly used nowadays, the former are inferior in permanent compression set which is an indication of sealability. Furthermore, they generate halogen compounds originating from the vulcanizing point of the compositions at the time of vulcanization molding which causes deterioration of adhesives. Therefore, no product having strong adhesion can be obtained and defective moldings result. Thus, the peroxide-vulcanizable fluorine-containing elastomers are limited in their use although they have excellent properties.